CN109434869B

CN109434869B - Active driving joint in cylindrical pair form

Info

Publication number: CN109434869B
Application number: CN201811531096.9A
Authority: CN
Inventors: 陈根良; 杜聪聪; 张壮; 王皓
Original assignee: Shanghai Jiaotong University
Current assignee: Shanghai Jiaotong University
Priority date: 2018-12-14
Filing date: 2018-12-14
Publication date: 2021-08-17
Anticipated expiration: 2038-12-14
Also published as: CN109434869A

Abstract

The invention discloses an active driving joint in a cylindrical pair form, which consists of a screw rod driving base and a movable platform. Wherein: the movable platform is connected and constrained with a screw rod of the screw rod driving base through an internal rotating structure. The rotating speeds and directions of the two motors of the screw rod driving base are controlled, so that the moving platform can simultaneously output a rotating motion effect and a translation motion effect. The driving element is arranged on the base of the machine frame, so that the movement inertia of the movable platform is greatly reduced, and the device has the characteristics of high precision and sensitive response. The moving platform does not need to carry a heavy driving motor, and has small inertia and sensitive response speed. Meanwhile, the motion precision is further improved by means of the high-precision transmission advantage of the ball screw. Meanwhile, a control line of the motor does not need to move together with the movable platform, so that the layout of the whole device is simplified, and the safety of mechanism operation is improved.

Description

Active driving joint in cylindrical pair form

Technical Field

The invention relates to the field of robots and automatic driving, in particular to an active driving joint in a cylindrical pair form.

Background

The cylindrical pair drive means that the tail end moving platform can simultaneously realize the translation and rotation effects, and the translation and rotation motions are mutually decoupled and can be respectively and independently controlled. The differential driving of the double screw rods is realized by controlling the rotating speed and the rotating direction of the two screw rods, so that the tail end movable platform simultaneously outputs a rotation motion and a translation motion. The driving element is arranged on the base of the rack, so that the movement inertia of the movable platform is greatly reduced, and the device has the characteristics of high precision, sensitive response and exquisite structure.

At present, a driving joint with two degrees of freedom generally adopts a linear combination mode of connecting a plurality of driving motors in series to achieve the motion effect of outputting a plurality of degrees of freedom. In order to achieve the motion effect of a cylindrical pair, a traditional mechanism generally needs to decompose rotation and movement, and the rotation and the movement are respectively driven by two motors which are independent of each other. The specific implementation is that a linear module such as a screw rod is driven by a motor in a moving mode, then a movable platform is installed on a nut of the screw rod, and a second rotary driving mechanism and a matched motor are fixed with the movable platform. In the process, a series of factors such as the driving power of the motor, the mass of the motor, the motion precision, the load inertia and the like need to be considered.

The existing cylindrical auxiliary driving mechanism adopts a multi-motor series connection mode to realize the movement effects of one rotation and one translation, and is often limited by the weight, the power and the reaction speed of a motor. In addition, the control line of the motor also needs to move along with the second motor on the movable platform, so that the layout of the whole device can be influenced, and even potential safety hazards in operation can be brought to the movement of the mechanism.

It has been found through a search of the prior art that a cylindrical auxiliary joint driving and transmission structure for SCARA and a method thereof are described in patent application with patent publication No. CN 107756436A. The joint is driven by two servo motors, and the movement and the rotation are realized by the transmission function of a synchronous belt component and a ball screw spline component. Wherein the moving part is driven by a single-stage belt in a speed reducing way; the rotating part is in speed reduction transmission by two-stage synchronous belts, and the intermediate shaft of the two-stage synchronous belts is fixedly installed through an independent intermediate shaft seat. The two-freedom-degree corresponding output of the tail end of the cylindrical pair is realized by the differential input of the two driving parts. The revolute pair and the sliding pair drive motor part, the belt wheel intermediate shaft fixing seat and the ball screw spline part are all directly arranged on the connecting rod. The independent belt wheel intermediate shaft fixing seat can better balance the shaft pressing force of the belt wheel, and can drive the intermediate shaft to move as a whole to adjust the pre-tightening of the synchronous belt. The configuration is used as a combined joint structure for rotation and movement of the rear half part of a common SCARA robot, and the rolling angle posture adjustment and the vertical movement of the tail end of the robot are realized. However, the application has the following disadvantages: the linear motion is driven by a lead screw mode, the lead screw needs to drive the two motors and the auxiliary transmission structures thereof to translate and rotate, the inertia of a motion part is large, the motion reaction speed is reduced, and the motion precision is also reduced. Meanwhile, the double motors are arranged in parallel, so that the whole device is large in structural size and inconvenient to arrange.

Disclosure of Invention

In view of the above defects in the prior art, the technical problem to be solved by the present invention is to provide a design for a cylindrical pair driving joint capable of outputting two degrees of freedom, i.e. translation and rotation, through differential driving of two lead screws, all motors are arranged on a base to be fixed, a tail end moving platform does not need to carry a heavy driving motor, the inertia of the moving platform is small, and the reaction speed is sensitive. Meanwhile, the motion precision is further improved by means of the high-precision transmission advantage of the ball screw.

In order to achieve the purpose, the invention provides an active driving joint in a cylindrical pair form, which comprises a screw rod driving base module and a movable platform module, wherein the screw rod driving base module comprises a first driving motor, a second driving motor, a first screw rod, a second screw rod, a first support, a second support, a first side edge and a second side edge, two ends of the first side edge and the second side edge are respectively fixed on the first support and the second support, the first driving motor is fixed on the first support, the second driving motor is fixed on the second support, two ends of the first screw rod and the second screw rod respectively penetrate through supporting bearings on the first support and the second support to realize axial fixation, the first driving motor is connected with the first screw rod through a coupler, and the second driving motor is connected with the second screw rod through a coupler;

the movable platform module comprises a gear box body, a sliding block, an upper cylindrical gear, a lower cylindrical gear, an output arm end cover, an upper nut and a lower nut, wherein the lower cylindrical gear is sleeved on the lower nut;

the sliding block can slide on the first side edge and the second side edge, the first screw rod penetrates through the upper nut and is in threaded connection with the upper nut, and the second screw rod penetrates through the lower nut and is in threaded connection with the lower nut;

furthermore, the screw rod driving base module also comprises a motor support, the first driving motor and the second driving motor are connected and fixed on the motor support through screws, and the motor support is respectively fixed on the first support and the second support;

further, the screw rod driving base module further comprises a flange pressing sheet, and the flange pressing sheet is installed between the supporting bearing and the first support and the second support.

Further, the first side edge and the second side edge are fixed on the first support and the second support through irregular-shaped fixing pieces;

furthermore, the gearbox body comprises a left gearbox body and a right gearbox body, and the left gearbox body and the right gearbox body are fastened and fixed in a screw fastening mode;

furthermore, the number of the sliding blocks is 4, and the sliding blocks are respectively fixed at two ends of the left gear box body and the right gear box body;

furthermore, the slide block is connected with the left gear box body and the right gear box body in a screw fastening mode;

furthermore, the output arm end cover is fixedly connected with the upper cylindrical gear in a screw fastening mode;

further, the first side edge and the second side edge are aluminum profiles;

further, when the rotating speeds and the directions of the first driving motor and the second driving motor are the same, the movable platform module outputs translation; when the rotating speeds of the first driving motor and the second driving motor are the same and the directions are opposite, the movable platform module outputs rotation; when the rotating speeds of the first driving motor and the second driving motor are different, the movable platform module simultaneously outputs translation and rotation.

Has the advantages that:

compared with the prior art, the invention provides the differential drive of the double screw rods, and the motion effects of one rotation and one translation are simultaneously output by the tail end moving platform by controlling the rotating speed and the rotating direction of the two screw rods. The driving element is arranged on the base of the machine frame, so that the movement inertia of the movable platform is greatly reduced, and the device has the characteristics of high precision and sensitive response. The tail end moving platform does not need to carry a heavy driving motor, and is small in inertia and sensitive in response speed. Meanwhile, the motion precision is further improved by means of the high-precision transmission advantage of the ball screw. Meanwhile, a control line of the motor does not need to move together with the movable platform, so that the layout of the whole device is simplified, and the operation safety of the mechanism is improved.

The conception, the specific structure and the technical effects of the present invention will be further described with reference to the accompanying drawings to fully understand the objects, the features and the effects of the present invention.

Drawings

FIG. 1 is an overall block diagram of a preferred embodiment of the present invention;

FIG. 2 is a side view of a movable platform module in accordance with a preferred embodiment of the present invention;

FIG. 3 is a cross-sectional view of a movable platform module in accordance with a preferred embodiment of the present invention;

fig. 4 is a side view of a screw driven base module in accordance with a preferred embodiment of the present invention.

Reference numerals:

1-a screw rod driving base module, 2-a movable platform module, 3-a sliding block, 4-a right gear box body, 5-a lower cylindrical gear, 6-an upper cylindrical gear, 7-an output arm end cover, 8-a left gear box body, 9-a first bearing, 10-an upper nut, 11-a second bearing, 12-a lower nut, 13-a first driving motor, 14-a first motor support, 15-an irregular-shaped fixing part, 16-a first support, 17-a supporting bearing, 18-a first side edge, 19-a second screw rod, 20-a coupler, 21-a second support and 22-a flange pressing sheet.

Detailed Description

As shown in fig. 1, in a preferred embodiment of the present invention, the present invention is composed of a screw driving base module 1 and a movable platform module 2. The two-degree-of-freedom spatial motion of the joint is realized by controlling the rotating speed and the direction of two driving motors of the screw rod driving base 1.

As shown in fig. 2 and 3, the moving platform module of the present invention includes: the gear box comprises a sliding block 3, a right gear box body 4, a lower cylindrical gear 5, an upper cylindrical gear 6, an output arm end cover 7, a left gear box body 8, a first bearing 9, an upper nut 10, a lower nut 12 and a second bearing 11, wherein the sliding block 3 is connected with the right gear box body 4 and the left gear box body in a screw fastening mode, the number of the sliding blocks is 4, the sliding blocks are respectively distributed at two ends of the left gear box body and the right gear box body, the lower cylindrical gear 5 is sleeved on the lower nut 12, the upper cylindrical gear 6 is sleeved on the upper nut 10, and the upper cylindrical gear and the lower cylindrical gear are in meshing transmission. The first bearing 9 and the second bearing 11 are respectively arranged in bearing grooves of the right gearbox housing 4 and the left gearbox housing 8 and are sleeved on stepped shafts at two ends of an upper nut 10 and a lower nut 12. And the end cover of the output arm is fastened with the end surface of the upper cylindrical gear 6 by screws. The right gearbox body 4 and the left gearbox body 8 are buckled and fixed in a screw fastening mode to form a gearbox body, and the gearbox body can be freely disassembled into the left gearbox body and the right gearbox body.

As shown in fig. 4, the screw driving base module 1 of the present invention includes: the device comprises a first driving motor 13, a second driving motor, a first motor support 14, a second motor support, an irregular-shaped fixing piece 15, a first support 16, a second support 21, a supporting bearing 17, a first side 18, a second side, a first screw rod, a second screw rod 19, a coupler 20 and a flange pressing piece 22, wherein the first driving motor 13 is fixedly connected with the section of the first motor support 14 through screws, the second driving motor is fixedly connected with the section of the second motor support through screws, and the first motor support and the second motor support are respectively fixed on the end faces of the first support 16 and the second support 21. The support bearing 17 is installed on the inner holes of the first support 16 and the second support 21, and two ends of the first screw rod and the second screw rod 19 respectively penetrate through the support bearing 17 on the first support 16 and the second support 21 to realize axial fixation. The first driving motor 13 and the second driving motor are connected with the first lead screw and the second lead screw 19 through a coupling 20, respectively. The first side 18 is erected on the first support 16 and the second support 21 and fixed on one side of the two supports in a screw fastening mode through the irregular-shaped fixing piece 15, and the second side is fixed on the other side of the two supports in the same mode, wherein the first side and the second side are both made of aluminum profiles. The flange pressing sheet 22 is installed on the inner holes of the first support and the second support, so that the axial position of the supporting bearing 17 can be adjusted, and the gap can be eliminated.

The first lead screw penetrates through the upper nut 10 and is in threaded connection with the upper nut, the second lead screw 19 penetrates through the lower nut 12 and is in threaded connection with the lower nut, and the sliding block can be matched with the first side and the second side, so that the movable platform is fixed between the first side and the second side and can slide between the two supports along the first side 18 and the second side. The basic transmission mode of the invention is as follows: the first driving motor and the second driving motor respectively drive the first lead screw and the second lead screw to rotate, the first lead screw drives the upper nut and the upper cylindrical gear to rotate, the second lead screw drives the lower nut and the lower cylindrical gear to rotate, the upper cylindrical gear and the lower cylindrical gear are in meshing transmission, and the translation of the movable platform module between the first support and the second support and the rotation of the output arm end cover are realized by controlling the rotating speeds and the directions of the two driving motors. When the rotating speeds and the directions of the first driving motor and the second driving motor are the same, the movable platform module outputs translation; when the rotating speeds of the first driving motor and the second driving motor are the same and the directions are opposite, the movable platform module outputs rotation; when the rotating speeds of the first driving motor and the second driving motor are different, the movable platform module simultaneously outputs translation and rotation.

The foregoing detailed description of the preferred embodiments of the invention has been presented. It should be understood that numerous modifications and variations could be devised by those skilled in the art in light of the present teachings without departing from the inventive concepts. Therefore, the technical solutions available to those skilled in the art through logic analysis, reasoning and limited experiments based on the prior art according to the concept of the present invention should be within the scope of protection defined by the claims.

Claims

1. An active driving joint in a cylindrical pair form comprises a screw rod driving base module and a movable platform module, and is characterized in that,

the screw rod driving base module comprises a first driving motor, a second driving motor, a first screw rod, a second screw rod, a first support, a second support, a first side edge and a second side edge, wherein two ends of the first side edge and the second side edge are respectively fixed on the first support and the second support;

the movable platform module comprises a gear box body, a sliding block, an upper cylindrical gear, a lower cylindrical gear, an output arm end cover, an upper nut and a lower nut, wherein the lower cylindrical gear is sleeved on the lower nut, the upper cylindrical gear is sleeved on the upper nut, the output arm end cover is fixed on the end face of the upper cylindrical gear, the sliding block is fixed on the gear box body, and the lower cylindrical gear and the upper cylindrical gear are in meshing transmission;

the sliding block can slide on the first side edge and the second side edge, the first screw rod penetrates through the upper nut and is in threaded connection with the upper nut, and the second screw rod penetrates through the lower nut and is in threaded connection with the lower nut.

2. The active drive joint of claim 1 in the form of a cylinder pair, wherein the lead screw drive base module further comprises a motor mount, the first and second drive motors being secured to the motor mount by a screw connection, the motor mount being secured to the first and second mounts, respectively.

3. The active drive joint of claim 1 in the form of a cylinder pair, wherein the lead screw drive base module further comprises a flange hold down tab mounted between a support bearing and the first and second mounts.

4. The active drive joint of claim 1, wherein the first and second sides are secured to the first and second abutments by irregular shaped fasteners.

5. The active drive joint of claim 1, wherein the gear housing comprises a left gear housing and a right gear housing, and the left gear housing and the right gear housing are fastened and fixed by screw fastening.

6. The active drive joint of claim 5 in the form of a cylindrical pair, wherein there are 4 of said blocks fixed to each end of said left and right gear housings.

7. The active drive joint of claim 6 in the form of a cylindrical pair, wherein the slide is connected to the left and right gearbox housing by screw fastening.

8. The active drive joint of claim 1 in the form of a cylindrical pair, wherein the output arm end cap is fixedly connected to the upper cylindrical gear by screw fastening.

9. The active drive joint of claim 1 in the form of a cylindrical pair, wherein the first side and the second side are aluminum profiles.

10. The active drive joint of claim 1 in the form of a cylindrical pair, wherein the movable platform module outputs a translational motion when the first and second drive motors are rotating at the same speed and direction; when the rotating speeds of the first driving motor and the second driving motor are the same and the directions are opposite, the movable platform module outputs rotation; when the rotating speeds of the first driving motor and the second driving motor are different, the movable platform module simultaneously outputs translation and rotation.